Two-Stage Precoding Matrix Resolution Adjustment
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Solution Overview
Problem
The existing LTE system's pre-coding codebook based on DFT vectors lacks flexibility in resolving codewords, leading to performance degradation due to fixed resolution determined by pre-defined DFT beam vectors.
Innovation Solution
A method and apparatus for generating a pre-coding matrix through linear weighting in a MIMO channel, involving a UE that determines and transmits first and second pre-coding indication information to adjust the resolution by weighting amplitudes and adjusting phases of beam vectors, allowing for a high-resolution pre-coding matrix.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a pre-coding codebook based on pre-defined DFT beam vectors is used, then the system has a simple and fixed structure, but the resolution of codewords cannot be adjusted flexibly, degrading system performance
Solution Approach 1:
The patent transforms the static, fixed-resolution codebook into a dynamic system where the resolution can be adjusted. This is achieved by introducing a resolution indication parameter that allows the terminal to select different resolution levels for codebook generation, enabling the system to adapt to varying channel conditions and performance requirements while maintaining a manageable codebook structure through hierarchical organization.
2Reliability
If high-resolution pre-coding matrices are generated through linear weighting, then the system performance and transmission reliability are improved, but the feedback overhead and processing complexity increase
Solution Approach 1:
The patent segments the pre-coding matrix generation process into distinct hierarchical levels (first-level codebook and second-level codebook). Each level handles specific aspects of the pre-coding function, allowing the system to achieve high resolution through coordinated selection across levels while managing feedback overhead by transmitting separate indication information for each level rather than encoding the entire high-dimensional matrix.
Solution Approach 2:
The patent introduces an additional dimension for codebook organization by creating a hierarchical two-level structure. This dimensional transformation allows the system to represent high-resolution pre-coding matrices through a compact combination of first-level and second-level codebook indices, effectively reducing the feedback overhead compared to transmitting a single high-dimensional matrix indicator.
Data Source
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AI summary
Disclosed are methods and apparatuses for transmitting coding indication information and determining a precoding matrix, for use in resolving the problem that the resolution of code words in a codebook generated by using a combination of a beam vector subgroup and column selection cannot be flexibly adjusted. The method comprises: user equipment determines first precoding indication information and second precoding indication information, the first precoding indication information corresponding to a first-stage precoding matrix, the first-stage precoding matrix comprising beam vectors in different polarizations, the second precoding indication information corresponding to a second-stage precoding matrix, the second-stage precoding matrix being used for performing amplitude weighting and phase adjusting on all beam vectors in each polarization in the first-stage precoding matrix, and the first-stage precoding matrix and the second-stage precoding matrix being used for generating a precoding matrix. Amplitude weighting and phase adjusting are performed on all beam vectors in each polarization in a first-stage precoding matrix, so that the resolution of a precoding matrix is flexibly adjusted, and the system performance is improved.